Which two code samples demonstrate valid methods for working with loops?

A.
DECLARE I INT DEFAULT 0;
Test_loop: LOOP
SET i =i +1;
IF i> =5 THEN
LEAVE test_loop;
END IF;
END LOOP test_loop;

B.
DECLARE i INT DEFAULT 0;
WHILE I < 5ITERATE
SET i = i +1;
END WHILE;

C.
DECLARE i INT DEFAULT 0;
WHILE i < 5 Do
SET i = i + 1;
END WHILE;

D.
DECLARE i INT DEFAULT 0;
Test _loop; LOOP
SET i =i +1;
IF i >=5 THEN LEAVE;
END IF;
END LOOP test_loop;